Seatbelt restraint systems for vehicles often include a pretensioner which is structured to apply tension to the seatbelt when an impending impact event such as an accident situation is detected. When the pretensioner is activated, the pretensioner eliminates any slack in the seatbelt, and thus controls the physical space between the occupant and the seatbelt. In this manner, the occupant of the seat is coupled with the seatbelt as the occupant initially moves forward relative to the seat, thereby controllably restraining the occupant, reducing occupant excursion, and preventing undue loads when the occupant moves forwardly into the seatbelt.